Chlorosubstituted bicyclic aldehyde



CHLOROSUBSTITUTED BICYCLIC ALDEHYDE Albert H. Haubein, Christiana, DeIassignor to Hercules lrsml vder Company, Wilmington, Del, a corporationof e aware No Drawing. Original application December 16, 1954, SerialNo. 475,817, now Patent No. 2,806,813, dated September 17, 1957. Dividedand this application July 3, 1957, Serial No. 669,715

1 Claim. (Cl. 260-598) This invention relates to the Diels-Alder adductof hexachlorocyclopentadiene and acrolein having the chemical formulal,4,5,6,7,7 hexachlorobicyclo(2.2.1)- 5heptene-2-carboxaldehyde.

The octachloro compound of the formula:

adduct of the formula 1,4,5,6,7,7-hexachlorobicyclo-(2.2.1)-5-heptene-2-carboxaldehyde 'which can be chlorinated withphosphorus pentachloride to yield the same octachloro compound depictedabove which is free of the by-products resulting from chlorination ofthe hexachlorocyclopentadiene-allyl chloride adduct. Thehexachlorocyclopentadiene-acrolein adduct of this formula is thus asuperior reagent for the preparation of insecticides.

The method of preparing the adduct of this invention and its use in thepreparation of insecticides is set forth in more detail in the followingexample where all parts and percentages are by weight.

Example A solution of 278 parts hexachlorocyclopentadiene and 56 partsacrolein in 45 parts xylene was heated under reflux while graduallyraising the temperature from about 60 C. to about 140 C. as the acroleinunderwent condensation with the hexachlorocyclopentadiene. This heatingprocess took 48 hours. The solvent was then removed at 100 C. underreduced pressure and the residue was sublimed at 100-125 C. at 0.7 mm.

pressure. The sublimedsolid amounting to 125 parts was1,4,5,6,7,7-hexachlorobicyclo(2.2.1) 5 heptenyl- Z-carboxaldehyde whichanalyzed 63.2% chlorine and 9.3% carbonyl.- This adduct was then heatedwith 200 parts phosphorus pentachloride at about 100 C. for 16 hours.The resulting product was taken up in ether, washed with water, withaqueous sodium hydroxide and then with water. The ether layer was thendried over anhydrous sodium sulfate. After distilling off the flies. Thesprayed flies were then anesthetized with oar-v 2,932,669 Patented A r.12, 1960 ether, the product was distilled to recover 106 parts 2-dichloromethyl 1,4,5,6,7,7 hexachlorobicyclo(2.2.l)-

5-heptene, B.P, 135-148 C./0.6 mm. which analyzed 73.6% chlorine.Infrared'absorption data showed this product (designated product A) tobe the same as that prepared by chlorination of thehexachlorocyclop'entadiene-allyl chloride adduct described hereinafterand designated product B.

Product B was made from the hexachlorocyclopentadiene-allyl chlorideadduct as follows A mixture of parts hexachlorocyclopentadiene and 38parts allyl chloride was heated in a sealed tube at 142-144 C. for 30hours. The resulting product was distilled to recover 13 partshexachlorocyclopentadione and parts2-chloromethyl-1,4,5,6,7,7-hexachlorobicyclo(2.2.'l)-5-heptene boilingat 96-106 C./0.15 mm. pressure, M.P. 52.454.2 C. when crystallized fromalcohol. Analysis of this product showed 71.0% chlorine.

A solution of parts2-chloromethyl-1,4,5,6,7,7-hexach1orobicyclo(2.2.1)-5-heptene in 520parts carbon tetrachloride was exposed to actinic light and heated to 75C. while passing chlorine gas into the solution. After 36 parts chlorinehad reacted, the reaction was stopped and the mixture was washed withaqueous sodium carbonate and water. The chlorinated 2-chloromethyl1,4,5,6,7,7 hexachlorobicyclo(2.2.1)-5-heptene was recovered as partsyellow viscous residue by distilling off the solvent upto 100 C. at 18mm, pressure. This chlorinated product analyzed 73.7% chlorine,corresponding to 2dichloromethyl-l,4,5,6,7,7,-hexachlorobicyclo(2.2.1)-5-heptene. Infraredabsorption spectra confirmed the structure as corresponding with thesame product made from the hexachlorocyclopentadiene-acrolein adduct ofthis invention and also confirmed the presence of the double bond.

The comparative toxicity to insects and to mammals of products A and Bis set forth in the table below.

1 Concentration in deodorized kerosene (mg. per 100 ml. solution)required for 50% kill in 20 hours.

2 Weight of product in mg. per kilogram of body weight required for 50%kill in 2 weeks.

The LD for housefiies was determined by dissolving the compound of theexamplein deodorized kerosene of,

different concentrations. A 0.8 ml, sample of each concentration wassprayed into a cage of 50 three-day-old bon dioxide and transferred toclean cages where they were left for 20 hours. The number of dead flieswas determined at the end of 20 hours and the concentration which killed50% of the flies was recorded as LD for houseflies in the tabulation.

The LD for albino rats was determined by feeding weighed rats in groupsof 5 measured amounts of a 5% solution (weight/volume) in corn oil bymeans of a stomach tube. Mortality records were noted at the end of twoweeks after administration. The weight of compound in mg. per kg. ofbody weight required to kill 50% of the rats in this period of time wastaken as LD in the tabulation,

The octachloro compound obtained by reaction of the adduct of thisinvention with PCl appears to have the optimum in toxicity to insectsand with minimum mammalian toxicity for its particular chlorine content.Further chlorination to a total .of 9 chlorine atoms de- 4 creases thetoxicity to insects but not to mammals. This application is a divisionof application Serial No. Accordingly, thme products find a wide utilityin the in- 475,817, filed December 16; 1954, now US. Patent NO.secticide field. p 2,806,813. The chlorinated compound obtained from theadduct What I claim and desire to protect by Letters Patent is:

of this invention 'is used as the sole toxic agent in pesti-- 5 As achemical compound 1, '0- cidal formulations or in admixture with minoramounts bicyclo(2.2.1)-5-heptene-2-carboxaldehyde.

of other toxicants for modification of the properties of the individualtoxicants. This utility is more fully de- 7 r 1 No referencescitedscribed in application Serial No. 475,817.

